Biology Unit 2 Flashcards
(43 cards)
What are the two groups animals can be divided into?
Vertebrates: Animals with a backbone
Invertebrates: Animals without a backbone
What two groups can plants be divided into?
Flowering and Non-flowering
What are the groups within invertebrates?
Sea anenomaes and jellyfish
Starfish and sea urchins
Worms
Molluses
Anthropods
What groups can vertebrates be split into?
Reptiles
Amphibians
Birds
Mammals
Fish
Explain the binomial naming system
The first name is the generic name and this is the genus to which the organism belongs
The second name is the specific name and this is the species
Why does an organism need a scientific name?
It is universal and the same in all languages
What is biodiversity?
The variety of different species in an area
Includes number of different species and how many in each of these species
Why is biodiversity important?
Provides food, potential foods, industrial materials, new medicines and for human well being
What are threats to biodiversity?
Habitat destruction
Invading species
Population increase
Pollution
Over exploitation
Describe the capture recapture method
Take a sample of the population
Mark each item
Put the items back into the population and ensure they are thoroughly mixed
Take a second sample and count how many of your sample are marked
What is biological control?
Using one organism to keep the numbers of another under control
E.g ladybirds can be used to get rid of aphids.
What is homeostasis?
The ability of the body to maintain a constant internal environment
Why is homeostasis important?
Metabolism operates only within a narrow range of temperature and pH and requires appropriate nutrients and water.
How does sweating work?
When you are too hot you will sweat. Sweat is produced by the sweat glands and travels up the sweat ducts and out of the sweat pores onto the surface. Here it will evaporate, taking excess body heat with it. Your body uses this mechanism to cool down.
What is vasodilation?
When you are too hot, Blood vessels in the skin dilate to allow blood flow close to the surface and radiate heat.
What is vasoconstriction?
When you are too cold, blood vessels in the skin constrict to keep blood deeper under the skin away from the surface and less heat is radiated.
Erection of hairs when too hot
The hair erector muscle relaxes, lowering the hair. A thin insulating layer is trapped above the skin. More heat is lost to the surroundings.
Erection of hairs when too cold
The hair erection muscle contracts raising the hairs. The hairs trap a layer of air around the body and insulate the body, keeping it warm.
How does shivering work?
Shivering is caused by involuntary contractions of the muscles. Muscle contractions require energy from which releases heat. This heat is used to warm the body.
What are the sense organs and their functions?
Eyes: vision- detecting changes in light
Ears: hearing- detecting vibrations
Balance- changes in position
Nose: smell- interpreting chemicals
Tongue: taste- interpreting chemicals
Skin: feel- detecting changes in temperature or pressure
What do the sense organs do?
Sense organs as groups have receptor cells which respond to specific stimuli and then relay this information as electrical impulses along neurons to the central nervous system
Why does our body need to react quickly?
Sometimes we need to react very quickly often to prevent harm or injury.
How do reflexes protect us?
Reflexes are fast and automatic to prevent harm/ injury
-Blinking
- Pupils dialating
-withdrawal reflex
What is the sclera (part of the eye)
Protective tough white outer coat of the eye
